Viessmann B2HF - Page 97

97
Displayed fault
code
System characteristics Cause Measures
F.384 Burner in a fault state Possible contamination of
gas line
■
Check gas line for contamination.
■
Check the gas supply pressure.
■
Replace gas fan if required.
Reset the appliance.
F.385 Burner in a fault state Short circuit, signal 1, ioni-
sation current.
BCU burner control unit
faulty.
Check IO electrode for earth fault.
If fault continues to persist, replace
BCU burner control unit (see
page 109).
Reset the appliance.
F.386 Burner in a fault state BCU burner control unit
faulty
Replace BCU burner control unit
(see page 109).
Reset the appliance.
F.387 Burner in a fault state Earth fault, ionisation cur-
rent. BCU burner control
unit faulty.
Check ionisation electrode and
connecting cable. If fault continues
to persist, replace BCU burner
control unit (see page 109).
Reset the appliance.
F.388 Burner in a fault state BCU burner control unit
faulty
Replace BCU burner control unit
(see page 109).
Reset the appliance.
F.395 Burner in a fault state IO electrode earth fault,
BCU burner control unit
faulty
Check ignition electrode for earth
fault. If fault continues to persist,
replace BCU burner control unit
(see page 109).
Reset the appliance.
F.396 Burner in a fault state BCU burner control unit
faulty
Replace BCU burner control unit
(see page 109).
Reset the appliance.
F.399 Burner in a fault state IO electrode earth fault,
BCU burner control unit
faulty
Check IO electrode for earth fault.
If fault continues to persist, replace
BCU burner control unit (see
page 109).
Reset the appliance.
F.400 Burner in a fault state BCU burner control unit
faulty
Replace BCU burner control unit
(see page 109).
Reset the appliance.
F.401 Burner in a fault state IO electrode earth fault,
BCU burner control unit
faulty
Check IO electrode for earth fault.
If fault continues to persist, replace
BCU burner control unit (see
page 109).
Reset the appliance.
F.402 Burner in a fault state BCU burner control unit
faulty
Replace BCU burner control unit
(see page 109).
Reset the appliance.
F.403 Burner in a fault state Ionisation electrode earth
fault, BCU burner control
unit faulty
Check IO electrode for earth fault.
If fault continues to persist, replace
BCU burner control unit (see
page 109).
Reset the appliance.
F.404 Burner in a fault state BCU burner control unit
faulty
Replace BCU burner control unit
(see page 109).
Reset the appliance.
Troubleshooting
Fault messages (cont.)
5593201
Diagnosis